Spectrum of appearances on CT and MRI of hepatic epithelioid hemangioendothelioma

Comparison of clinical and MRI features of hepatic angiosarcoma and epithelioid hemangioendothelioma

OBJECTIVE

Differentiating hepatic epithelioid hemangioendothelioma (EHE) and angiosarcoma (AS), the two most common vascular tumors in the liver, is important due to disparities in their prognosis and treatment. We aimed to compare clinical and MRI features of the two tumors.

METHODS

This retrospective study included patients with pathologically-confirmed AS or EHE who underwent MRI using gadoxetate disodium between 2008 and 2023. Two radiologists independently reviewed MR images. Wilcoxon rank sum and Fisher's exact tests were used to compare clinical and imaging features. Overall survival was compared using restricted mean survival time at 3 years.

RESULTS

32 patients with AS (18 women [56.3%]; median age, 68 years) and 38 with EHE (24 women [63.2%]; 51 years) were included. Patients with AS were generally older (81.3% ≥ 60 years; P < 0.001), had more frequent laboratory abnormalities (P ≤ 0.018), and poorer overall survival (11.2 vs. 31.8 months; P < 0.001) than those with EHE. On MRI, a large dominant mass accompanied by smaller nodules (14/32, 43.8%), often with ill-defined margins (15/32, 46.9%) was prevalent in AS; compared with nodules of similar sizes (24/38, 63.2%; P = 0.015) with well-defined margin (30/38, 78.9%; P = 0.002) in EHE. Cirrhotic appearance of the liver was more frequent in AS (62.5%, P < 0.001), along with decreased parenchymal enhancement on hepatobiliary phase (31.3%, P < 0.001) and ascites (37.5%, P = 0.010). AS frequently presented with avid enhancement of bizarrely-shaped foci, with a centrifugal enhancement pattern. In comparison, targetoid appearance was characteristic of EHE (78.9% on T2-weighted, 54.1% on diffusion-weighted, 65.8% on multiphase images) (P ≤ 0.002), with enhancement degree typically lower than that of the aorta. On hepatobiliary phase, all the AS exhibited hypointensity, while 39.5% of EHE showed targetoid appearance (P < 0.001).

CONCLUSION

Patients aged ≥ 60 years presenting with laboratory abnormalities, typically with a large dominant mass accompanied by smaller nodules, exhibiting avid, bizarre, and centrifugal enhancement-particularly in the cirrhotic-appearing liver-suggests the likelihood of AS over EHE.

Discontinuous peripheral enhancement of focal liver lesions on CT and MRI: outside the box of typical cavernous hemangioma

The discontinuous peripheral enhancement is a pattern of enhancement usually attributed to typical cavernous hemangioma, that is the most common benign solid lesion of the liver. The discontinuous peripheral enhancement, however, may be encountered in many other benign and malignant focal liver lesions as an atypical presentation or evolution, and hemangiomas with discontinuous peripheral hyperenhancement on hepatic arterial phase may not always have the typical post-contrast pattern on portal venous and delayed phases. Therefore, abdominal radiologists may be challenged in their practice by lesions with discontinuous peripheral enhancement. This pictorial essay aims to review the spectrum of benign and malignant focal liver lesions that may show discontinuous peripheral enhancement. A particular point of interest is the diagnostic tree pathway that may guide the radiologists in the differential diagnosis.

Hepatic epithelioid hemangioendothelioma with TFE3 rearrangement: a case report and literature review

Epithelioid hemangioendothelioma (EHE) is a rare low-grade malignant tumor of vascular origin. It may be confusing as its manifestations of multifocal lesions on imaging and epithelial histomorphology in pathology. EHE is easy to be mistaken for a metastatic tumor by radiologists and clinicians. Correct diagnosis and therapy are important owing to the variable clinical course and special treatment. EHEs harbor major CAMTA1 rearrangement and <5% TFE3 rearrangement. Meanwhile, EHE with TFE3 rearrangement has distinctive morphology features. Currently, there are only two cases of hepatic EHE with TFE3 rearrangement reported, we present another case here that occurred in a 34-year-old female. Both the clinician and radiologist provisionally considered it as a metastatic tumor. The tumor cells have mild atypia but infiltrative growth patterns like benign vascular tumors. Our case is unique mainly in that the absence of its characteristic well-defined vessels, and the presence of unreported morphology of intraluminal papillary proliferation of tombstone or hobnail endothelial cells. The final diagnosis of EHE with TFE3 rearrangement was made by combining morphological, immunohistochemical, and molecular test results. The patient did not receive any treatment according to her condition and no change was detected in the mass's size and number on CT images during 3.5 years of follow-up.

The challenges of hepatic epithelioid hemangioendothelioma: the diagnosis and current treatments of a problematic tumor

BACKGROUND

Hepatic epithelioid hemangioendothelioma (HEHE) is a malignant vascular tumor known for its rarity. The different types of this hepatic tumor (single, multiple-nodular or diffused) indicate different prognosis and treatment plans. However, the heterogenic clinical manifestation creates a dilemma and a wide range of challenges when attending to HEHE patients. This review addresses the unique profile and clinical challenges that complicate the diagnosis and treatment of HEHE while focusing on current therapeutic strategies and their limitations.

MAIN TEXT

The unclear etiology is a challenging feature of HEHE. The exact involvement of potential risk factors and mechanism of development are still undefined. Relevant genetic alterations like WWTR1-CAMTA1 fusion have been investigated; however, they are only applicable as diagnostic markers and their influence on therapeutic efficacy is largely unknown. Other characteristics include asymptomatic manifestation, lack of unique hepatic functional alterations, high rates of misdiagnosis and late-stage identification when metastases already exist. Currently, tissue biopsy is the main tool to establish a definite diagnosis but is challenged with the limited awareness to suspect HEHE at early stages and the lack of relevant guidelines due to the rarity and the insufficiency of relevant research. The absence of treatment guidelines is the greatest challenge of HEHE. Generally, Surgical approaches are recommended due to the benefits of prolonged survival and enhanced prognosis. Nonetheless, only a minority of patients are eligible for resections while liver transplants are faced with severe insufficiency of donor organs and long wait-lists. On the other hand, a variety of non-surgical treatments (like anti-angiogenic agents, interferon alpha-2B and sirolimus) are presented with a promising potential. However, relevant studies are challenged with limited sample-sizes and lack of prospective designs.

CONCLUSION

Regardless to decades passing since its discovery, HEHE still creates a dilemma due to its challenging clinical profile and lack of treatment guidelines. Raising awareness of HEHE in clinical practices improves the ability to diagnose this rare tumor at early stages and develop stronger research strategies and treatment guidelines to regulate the medical care provided to HEHE patients.

Comprehensive evaluation of clinical outcomes in hepatic epithelioid hemangioendothelioma subsets: insights from SEER Database and departmental cohort analysis

Background

Epithelioid hemangioendothelioma (EHE), is an uncommon, intermediate-grade malignant vascular tumor that can manifest in diverse organs, including the liver, lungs, and bones. Given its unique malignancy profile and rarity, there lacks a consensus on a standardized treatment protocol for EHE, particularly for hepatic epithelioid hemangioendothelioma (HEHE). This study aims to elucidate factors influencing the clinical prognosis of EHE by analyzing data from the SEER database, complemented with insights from a departmental cohort of 9 HEHE cases. Through this, we hope to shed light on potential clinical outcomes and therapeutic strategies for HEHE.

Methods

Using SEER data from 22 registries, we analyzed 313 liver cancer patients with ICD-O-3 9130 and 9133 histology. Twelve variables were examined using Cox regression and mlr3 machine learning. Significant variables were identified and compared. Clinical data, imaging characteristics, and treatment methods of nine patients from our cohort were also presented.

Result

In univariate and multivariate Cox regression analyses, Age, Sex, Year of diagnosis, Surgery of primary site, Chemotherapy, and Median household income were closely related to survival outcomes. Among the ten survival-related machine learning models, CoxPH, Flexible, Mboost, and Gamboost stood out based on Area Under the Curve(AUC), Decision Curve Analysis(DCA), and Calibration Curve Metrics. In the feature importance analysis of these four selected models, Age and Surgery of primary site were consistently identified as the most critical factors influencing prognosis. Additionally, the clinical data of nine patients from our cohort not only demonstrated unique imaging characteristics of HEHE but also underscored the importance of surgical intervention.

Conclusion

For patients with resectable HEHE, surgical treatment is currently a highly important therapeutic approach.

Benign and malignant focal liver lesions displaying rim arterial phase hyperenhancement on CT and MRI

Rim arterial phase hyperenhancement is an imaging feature commonly encountered on contrast-enhanced CT and MRI in focal liver lesions. Rim arterial phase hyperenhancement is a subtype of arterial phase hyperenhancement mainly present at the periphery of lesions on the arterial phase. It is caused by a relative arterialization of the periphery compared with the center of the lesion and needs to be differentiated from other patterns of peripheral enhancement, including the peripheral discontinuous nodular enhancement and the corona enhancement. Rim arterial phase hyperenhancement may be a typical or an atypical imaging presentation of many benign and malignant focal liver lesions, challenging the radiologists during imaging interpretation. Benign focal liver lesions that may show rim arterial phase hyperenhancement may have a vascular, infectious, or inflammatory origin. Malignant focal liver lesions displaying rim arterial phase hyperenhancement may have a vascular, hepatocellular, biliary, lymphoid, or secondary origin. The differences in imaging characteristics on contrast-enhanced CT may be subtle, and a multiparametric approach on MRI may be helpful to narrow the list of differentials. This article aims to review the broad spectrum of focal liver lesions that may show rim arterial phase hyperenhancement, using an approach based on the benign and malignant nature of lesions and their histologic origin. CRITICAL RELEVANCE STATEMENT: Rim arterial phase hyperenhancement may be an imaging feature encountered in benign and malignant focal liver lesions and the diagnostic algorithm approach provided in this educational review may guide toward the final diagnosis. KEY POINTS: Several focal liver lesions may demonstrate rim arterial phase hyperenhancement. Rim arterial phase hyperenhancement may occur in vascular, inflammatory, and neoplastic lesions. Rim arterial phase hyperenhancement may challenge radiologists during image interpretation.

Ultrasound findings of hepatic epithelioid hemangioendothelioma: comparison with other malignant hepatic tumors

PURPOSE

To investigate and compare the ultrasonic features of hepatic epithelioid hemangioendothelioma (HEHE) and other common hepatic malignancies, such as hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (ICC) and hepatic metastatic tumor (HMT).

METHODS

A total of 37 patients with pathologically proven HEHE, 37 HCC cases, 37 ICC cases, and 37 HMT cases were enrolled from single hospital. The clinical characteristics and ultrasonic features of all cases were summarized and statistically analyzed.

RESULTS

There were significant differences in sex and age between the HEHE group and other three groups (P < 0.001). The probability of HEHE infection with hepatitis B virus was lower than that of HCC and ICC groups (P < 0.05). The probability of elevated serum tumor markers in HEHE was significantly lower than that in the other three groups (P < 0.05). On conventional ultrasound (CUS), the probability of multiple lesions in HEHE was significantly higher than that in the other three groups (P < 0.05). On contrast-enhanced ultrasound (CEUS), the time to wash out in HEHE was significantly shorter than that of the other three groups (P < 0.001). The proportion of synchronous or slow enhancement in HEHE was significantly higher than that of the other three groups (P < 0.001). The proportion of HEHE with iso- or hypo-enhancement was significantly higher than in HCC and HMT groups (P < 0.05).

CONCLUSION

HEHE mainly performed multiple hypoechoic lesions on CUS and displayed greater odds of synchronous enhancement in arterial phase, iso- or hypo-enhancement in peak time and wash out more quickly on CEUS, which allowed for differentiation from other common malignant tumors.

Review on Pediatric Malignant Focal Liver Lesions with Imaging Evaluation: Part II

Malignant focal liver lesions (FLLs) represent various kinds of epithelial and mesenchymal tumors. In pediatric patients, the understanding of pediatric liver diseases and associated imaging manifestations is essential for making accurate diagnosis and differential diagnosis. This paper will discuss the latest knowledge of the common pediatric malignant FLLs, including undifferentiated embryonal sarcoma, rhabdomyosarcoma, epithelioid hemangioendothelioma, angiosarcoma, and malignant rhabdoid tumor. Medical imaging features are not only helpful for clinical diagnosis, but can also be useful in the evaluation and follow-up of pre- and post-treatment. The future perspectives of contrast-enhanced ultrasound (CEUS) enhancement patterns of FLLs in pediatric patients are also mentioned.

Hepatic epithelioid hemangioendothelioma-a single-institution experience with 51 cases

Objectives

The aim of the present study was to describe the experience at a single institution in the management of hepatic epithelioid hemangioendothelioma (HEHE).

Methods

We included 51 patients with histologically confirmed HEHE. We performed log-rank (Cox-Mantel) survival analyses using Kaplan-Meier methods to test differences in survival between patients in different groups. Univariate Cox regression analyses and multivariate proportional hazards regression model were carried out to identify independent prognostic factors.

Results

Different imaging modalities were used to diagnose HEHE with various presentations. Liver resection (LR), liver transplantation (LT), systemic treatment (ST), and surveillance had been used in our study. A significant difference was noted between the LR group and the surveillance group with respect to mean survival (p = 0.006), as was in the LR group and the ST group (p = 0.036), and in surgical approach (LR and LT) and nonsurgical approach (ST and surveillance) (p = 0.008). The mean survival between the ST group and the surveillance group was not significantly different (p = 0.851). LR (p = 0.010) and surgical approach (p = 0.014) were favorable predictors of outcome, while macrovascular invasion (MaVI) (p = 0.037), lung metastasis (p = 0.040), and surveillance (p = 0.033) were poor prognostic factors in univariate analysis. Multivariate analysis showed that LR (p = 0.010) and surgical approach (p = 0.014) were independently associated with good OS, while surveillance (p = 0.033) was independently associated with poor OS. After adjusting for confounding factors, patients in the LR group have much better OS than those in the surveillance group (p = 0.013). However, there was no significant difference in OS between the LR group and ST group (p = 0.254), as was in the ST group and the surveillance group (p = 0.857).

Conclusions

The definitive diagnosis of HEHE was dependent on histopathology, and it was not possible to make a specific diagnosis without biopsy because the radiological findings were similar to those in some hepatic malignancies. ST was not recommended for patients who were not candidates for surgical approaches, and surgical approaches should be warranted regardless of disease stage. The retrospective nature and the small size of the data limited the generalizability of the study, designing a worldwide database that contains all data about patients with HEHE independent of their therapy, which was highly recommended.

Characteristic contrast‑enhanced ultrasound findings of hepatic epithelioid haemangioendothelioma: A case report and literature review

Hepatic epithelioid hemangioendothelioma (HEHE) is a rare liver tumor, which is usually diagnosed by pathological examination, since the diagnostic imaging criteria remain to be defined. However, contrast-enhanced ultrasound (CEUS) may reveal the characteristic features of HEHE to aid diagnosis. In the present study, two-dimensional ultrasound examination of a 38-year-old male patient showed a mass in the right liver. CEUS showed an S5 segment hypoechoic nodule, and imaging features resulted in the diagnosis of HEHE. Surgery was shown to be an appropriate and successful treatment for HEHE. In conclusion, CEUS may be valuable for the diagnosis of HEHE, thereby avoiding the serious consequences of misdiagnosis.

CT and MRI features of hepatic epithelioid haemangioendothelioma: a multi-institutional retrospective analysis of 15 cases and a literature review

OBJECTIVE

To improve the current imaging understanding of MRI or CT for hepatic epithelioid haemangioendothelioma (HEHE) to aid in its successful preoperative diagnosis.

METHODS

The imaging features of 15 patients (median age 38.6, range 20-71; 7 M/8 F) from eight institutions with pathologically confirmed HEHE were retrospectively analysed. Additionally, the CT/MR imaging features of 180 patients in 15 literature publications were collected, analysed and compared with our case series.

RESULTS

Fifteen patients underwent CT and MRI (n = 2), CT (n = 9) or MR (n = 8) scans. A total of 92.9% (13/14) of the patients were initially diagnosed with other lesions on imaging. A total of 86.7% (13/15) were multifocal. Nodules (11/15, 73.3%) were predominantly peripheral in distribution (12/15, 80.0%). Some cases were associated with hepatic capsular retraction (13/15, 86.7%), "target signs" (8/15, 53.3%) and "lollipop signs" (5/15, 33.3%). Peripheral enhancement of various shapes in the early phase with a progressive centripetal filling was the most common pattern of enhancement (12/15, 80.0%). Abnormal vascularity was seen in 50.7% (6/15) of the patients. Suspicious tumour thromboses in the inferior vena cava were seen in 3 (20.0%) of the patients. Two of the 15 patients (13.3%) had a history of smoking.

CONCLUSIONS

HEHEs have common distinctive features, including multifocal lesions that are predominantly peripheral, "target signs", "lollipop signs", hepatic capsular retraction and peripheral enhancement of various shapes in the early phase with progressive centripetal filling. Additional aggressive imaging features that may be valuable clues to the diagnosis can be identified by CT or MRI.

A review of hepatic epithelioid hemangioendothelioma-Analyzing patient characteristics and treatment strategies

BACKGROUND

Hepatic epithelioid hemangioendothelioma (HEH) is a rare vascular tumor of unknown etiology and unpredictable natural history. To date, no large-scale studies have been published evaluating this disease due to its rare occurrence.

METHODS

The National Cancer Database was reviewed between 2004 and 2016 to identify patients with HEH. Univariate analysis with overall survival (OS) was performed by Cox proportional hazards model. Kaplan-Meier method was used to create OS curves and compared using the log-rank test.

RESULTS

We identified 229 patients with HEH. The majority of patients were female (61.1%), white (84.3%), and had a Charlson-Deyo score of 0 (75%). Chemotherapeutic intervention was seen in 26% of the patients while 33% received surgical intervention in the form of wedge/segmental liver resection (n = 27), hepatectomy lobectomy/extended lobectomy (n = 18), and liver transplant (n = 22). Five-year survival in surgical patients was 90.5%, 66.5% and 81%, respectively (p = 0.485). Age greater than 55 years (hazard ratio [HR], 2.78; p < 0.001), Asian ethnicity compared to white (HR, 2.84; p = 0.012), and a higher Charlson-Deyo score (score 1: HR, 2.28; p < 0.001 and score ≥2: HR, 2.76; p = 0.011) were associated with worse OS.

CONCLUSION

Treatment for HEH remains variable with only a third of the patients undergoing surgery. International collaboration is necessary to determine the optimal treatment for this rare disease.

Updated information regarding management of hepatic epithelioid hemangioendothelioma

Hepatic epithelioid hemangioendothelioma (HEHE) is a rare hepatic vascular tumor with a borderline biological behavior between hemangioma and hemangiosarcoma. It tends to be multiple or diffuse subcapsular lesions across the liver but has no characteristic clinical manifestations or imaging findings. On computed tomography and magnetic resonance imaging, these lesions usually have a hypodense appearance with heterogeneous enhancement and a "halo sign" or "lollipop sign" may be evident in some cases. HEHE is diagnosed mainly based on a pathological examination along with differential immunohistochemical markers such as CAMTA1, CD31, CD34, CD10, vimentin, and factor VIII antigen. Currently, there are no standardized treatment guidelines for HEHE, and surgery (curative resection and liver transplantation) remains the mainstay of treatment. Studies have indicated that extra-hepatic metastasis might not be a contraindication for resection or transplantation. Systemic chemotherapeutic agents including doxorubicin, vincristine, interferon-a, 5-fluorouracil, and thalidomide, as well as VEGF-related agents are being investigated, but no agents have been approved for the treatment of HEHE.

Primary Hepatic Epithelioid Hemangioendothelioma Masquerading as a Hepatic Abscess With Infective Picture: A Case Report

Hepatic endotheiloid hemangioendothelioma (EHE) commonly presents with multilobar involvement with locally aggressive behavior. In most cases, it presents with right upper quadrant abdominal pain, hepatomegaly, and weight loss with metastasis commonly to the lung. We present a 33-year-old woman with hepatic EHE with an initial presentation mimicking hepatic abscess and imaging findings misleading for metastatic liver lesions. It was confirmed on pathology with immunohistochemistry, but the patient could not survive due to her late presentation and the presence of metastatic lesions in the lung.

Imaging Spectrum of Intrahepatic Mass-Forming Cholangiocarcinoma and Its Mimickers: How to Differentiate Them Using MRI

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary hepatic malignancy, with mass-forming growth pattern being the most common. The typical imaging appearance of mass-forming ICC (mICC) consists of irregular ring enhancement in the arterial phase followed by the progressive central enhancement on portal venous and delayed phases. However, atypical imaging presentation in the form of hypervascular mICC might also be seen, which can be attributed to distinct pathological characteristics. Ancillary imaging features such as lobular shape, capsular retraction, segmental biliary dilatation, and vascular encasement favor the diagnosis of mICC. Nevertheless, these radiological findings may also be present in certain benign conditions such as focal confluent fibrosis, sclerosing hemangioma, organizing hepatic abscess, or the pseudosolid form of hydatid disease. In addition, a few malignant lesions including primary liver lymphoma, hemangioendothelioma, solitary hypovascular liver metastases, and atypical forms of hepatocellular carcinoma (HCC), such as scirrhous HCC, infiltrative HCC, and poorly differentiated HCC, may also pose a diagnostic dilemma by simulating mICC in imaging studies. Diffusion-weighted imaging and the use of hepatobiliary contrast agents might be helpful for differential diagnosis in certain cases. The aim of this manuscript is to provide a comprehensive overview of mICC imaging features and to describe useful tips for differential diagnosis with its potential mimickers.

Clinical characteristics and CT features of hepatic epithelioid haemangioendothelioma and comparison with those of liver metastases

BACKGROUND

To analyse clinical characteristics and computer tomography (CT) findings of hepatic epithelioid haemangioendothelioma (HEH) and to determine differential features compared with liver metastasis (LM).

METHODS

This retrospective study included 80 patients with histopathologically confirmed HEH (n = 20) and LM (n = 60) of different primary tumours who underwent dynamic contrast-enhanced CT scans. CT findings included the location, contour, size, number, margin, and density of lesions, the patterns and degree of contrast enhancement of lesions, vascular invasion and changes in other organs. The enhancement ratio (ER) and tumour-to-normal parenchyma ratio (TNR) were calculated. Receiver operating characteristic curves (ROCs) were used to determine areas under the curve (AUCs).

RESULTS

About 65% of HEH lesions were located in submarginal areas. Significant differences were observed between HEH and LM patients in age, sex, and tumour marker positivity (p < 0.05). HEH showed minimal to slight enhancement, thin ring-like enhancement in arterial phase, and slight, homogeneous, progressive enhancement in the portal phase. HEH presented capsule retraction, and the "target" sign and the "lollipop" sign were significantly more frequent than in LM (p < 0.05). The ER and TNR in the arterial phase of HEH were lower than those of LM (p < 0.05). AUCs of ER and TNR in the arterial phase were 0.74 and 0.73, respectively.

CONCLUSION

Lesions in subcapsular locations, capsular retraction, slight and thin ring-like enhancement, "target" and "lollipop" signs and lower ER and TNR in the arterial phase may represent important features of HEH compared with LM.

Hepatic epithelioid hemangioendothelioma simulating liver metastasis: A case report

Introduction

Hepatic epithelioid hemangioendothelioma (HEHE) is a rare tumor of vascular origin. Liver involvement is often multinodular simulating metastases. Herein, we report a rare case of HEHE mimicking liver metastases in a female patient.

Case presentation

A 43-years-old female patient, presented with complaints of pain in the right upper quadrant. Laboratory tests were all within the normal range. Abdominal ultrasound revealed multiple heterogeneous hypoechoic liver lesions. A thoracic and abdominopelvic computed tomography showed bilateral pulmonary micronodules with multiple hypodense hepatic nodules involving both lobes. Percutaneous ultrasound-guided biopsy with pathological study and immunohistochemistry staining revealed the diagnosis of hepatic epithelioid hemangioendothelioma.

Discussion

HEHE usually involves both liver lobes with three radiological presentations: single nodular, multiple nodular, or diffuse types, the diffuse type reflects an advanced stage. 3/4 of the cases are initially misdiagnosed as liver metastases or primary liver tumors. The pathological study with the immunochemistry stainings confirms the diagnosis. There is no standard treatment for HEHE due to its rarity and lack of prospective randomized studies.

Conclusion

HEHE is a rare tumor of vascular origin of unknown etiology with malignant potential and unpredictable course. The therapeutic management of this rare condition is not codified and is discussed on a case-by-case basis. Surgical treatment remains the best option with an excellent outcome.

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Hepatic epithelioid hemangioendothelioma is a rare tumor of vascular origin.

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The Clinical presentation and the radiological findings are not specific.

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Final Diagnosis is made upon pathological study and immunohistochemistry staining.

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Surgical treatment remain the treatment of choice.

Epithelioid hemangioendothelioma: evaluation by 18F-FDG PET/CT

PURPOSE

The purpose of this study was to evaluate the imaging characteristics of epithelioid hemangioendothelioma (EHE) on staging ¹⁸F-FDG PET/CT.

MATERIALS AND METHODS

An IRB-approved retrospective review was conducted for patients with biopsy-proven EHE who underwent FDG PET/CT at our institution between 2005 and 2019. Patients with a history of surgery, chemotherapy, or radiotherapy prior to PET/CT were excluded. PET/CT exams were analyzed, noting metabolic activity, distribution of involvement, and CT morphologic features. PET/CT findings were correlated with comparative CT and MRI performed within three months.

RESULTS

There were 35 patients [21 females, 14 males; average age 55.1±16.9 years (range 15-82 years)]. 18/35 patients (52%) had more than one organ affected on PET/CT. The most common sites were liver [21/35 (60%)], lung [(19/35 (54%)], bone [5/35 (14%)], lymph nodes [4/35 (11%)], and vasculature [4/35 (11%)]. Most patients [30/35, (86%)] presented with multiple lesions. The average largest lesion dimension was 4.0±3.6 cm (range 0.6-15.0 cm). The average SUVmax of the most metabolically active lesion at any site was 5.3±3.3 (range 1.2-17.1), and for bone was 7.9±5.4 (range 3.5-17.1), liver was 5.1±2.1 (range 2.6-10.5), and lung was 3.0±1.9 (range 1.2-8.5). Of patients with pulmonary lesions, 9/19 (47%) showed calcification, and 4/19 (21%) had nodules that were either non FDG-avid or too small for accurate SUV assessment. Of patients with hepatic lesions, 11/21 (52%) demonstrated capsular retraction, and 12/21 (57%) were found to have additional hepatic lesions on contrast-enhanced CT or MRI that were occult on PET/CT.

CONCLUSION

EHE demonstrates variable, but most commonly moderate FDG activity on PET/CT. The most common sites of disease are the liver, lungs, and bones, and most patients present with multiple lesions and more than one organ involved. Given the intrinsic metabolic activity and multi-organ involvement, FDG PET/CT represents an attractive modality for EHE evaluation. However, it may be best used in combination with CT or MRI given that EHE pulmonary or hepatic lesions may be missed by PET/CT.

Unusual Primary Neoplasms of the Adult Liver: Review of Imaging Appearances and Differential Diagnosis

The radiological appearance of common primary hepatic tumors such as hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) is widely recognized. Hepatic masses with unusual histology are occasionally encountered, but seldom suspected on imaging. However, many possess characteristic imaging findings, which when assessed along with the clinical and demographic background and serum tumor markers, may enable a prospective diagnosis. This review attempts to familiarize the reader with the clinicopathological characteristics, imaging manifestations, and differential diagnosis of these unusual liver tumors in adults. Biphenotypic primary liver carcinoma is suspected in masses showing distinct areas of HCC and CCA-type enhancement pattern in cirrhotic livers. Fibrolamellar carcinoma occurs in young individuals without underlying chronic liver disease and shows a characteristic T2-hypointense scar frequently showing calcification. Perivascular epithelioid cell tumors are differentials for any arterial hyperenhancing mass in the noncirrhotic liver, particularly in patients with tuberous sclerosis. Multifocal subcapsular tumors showing target-like morphology, capsular retraction and "lollipop" sign are suspicious for epithelioid hemangioendothelioma. On the other hand, multiple hemorrhagic lesions showing patchy areas of bizarre-shaped arterial phase hyperenhancement are suspicious for angiosarcoma. Primary hepatic lymphoma (PHL) is suspected when patients with immunosuppression present with solitary or multifocal masses that insinuate around vessels and bile ducts without causing luminal narrowing. Intense diffusion restriction and low-level homogeneous or target-like enhancement are also ancillary features of PHL. Primary hepatic neuroendocrine tumor shows uptake on Ga-68 DOTANOC PET/CT. Although a straightforward diagnosis may be difficult in these cases, awareness of the characteristic imaging appearances is helpful in suspecting the diagnosis.

Laparoscopic resection of hepatic epithelioid hemangioendothelioma: report of eleven rare cases and literature review

BACKGROUND

Hepatic epithelioid hemangioendothelioma (HEHE) is an extremely rare borderline tumor of vascular endothelial origin. Laparoscopic resection of HEHE has never been reported.

METHODS

The clinical data of eleven patients with HEHE (4 women and 7 men) who were diagnosed and treated at the Union Hospital (Wuhan, China), and Wuhan Asia General Hospital (Wuhan, China), between March 2012 and July 2020 were analyzed retrospectively.

RESULTS

The mean age of HEHE patients was 42.4 ± 13.9 years (range 22-67 years). All patients underwent laparoscopic surgery alone or in combination with radiofrequency ablation. Most tumors showed aggressive growth or metastasis. By immunohistochemistry, tumor cells were positive for CD31, CD34, ERG, PCK, FLi-1, TFE-3, and Ki-67 (labeling index range, 5-15%). In one of the patients, the tumor was accompanied by partial necrosis with a local appearance of epithelioid angiosarcoma. Postoperative adjuvant treatment included chemotherapy, sorafenib, and Huaier granule. As of July 2020, the median follow-up duration was 36 months (range, 9-60 months), with 2 (18.2%) patients experiencing tumor recurrence.

CONCLUSIONS

This is the first report of laparoscopic hepatectomy of HEHE. Curative laparoscopic hepatectomy might be an acceptable treatment for appropriate HEHE patients.

Hepatic epithelioid hemangioendothelioma: Update on diagnosis and therapy

With an estimated incidence of only 1-2 cases in every 1 million people, hepatic epithelioid hemangioendothelioma (HEHE) is a rare vascular endothelial cell tumor occurring in the liver and consisting of epithelioid and histiocyte-like vascular endothelial cells in mucus or a fibrotic matrix. HEHE is characterized as a low-to-moderate grade malignant tumor and is classified into three types: solitary, multiple, and diffuse. Both the etiology and characteristic clinical manifestations of HEHE are unclear. However, HEHE has a characteristic appearance on imaging including ultrasound, magnetic resonance imaging, and positron emission tomography/computerized tomography. Still, its diagnosis depends mainly on pathological findings, with immunohistochemical detection of endothelial markers cluster of differentiation 31 (CD31), CD34, CD10, vimentin, and factor VIII antigen as the basis of diagnosis. Hepatectomy and/or liver transplantation are the first choice for treatment, but various chemotherapeutic drugs are reportedly effective, providing a promising treatment option. In this review, we summarize the literature related to the diagnosis and treatment of HEHE, which provides future perspectives for the clinical management of HEHE.

Fast-growing epithelioid hemangioendothelioma of the liver: A case report

RATIONALE

Hepatic epithelioid hemangioendothelioma (HEH) is a rare vascular tumor of the liver with malignant potential. It can be of solitary type, multifocal type, or diffuse type. Although there are some characteristic features on radiologic imaging, the definitive diagnosis of HEH is based on histopathology. The surgical treatment of HEH includes liver resection and transplant.

PATIENT CONCERNS

A middle-aged woman presented with easy fatiguability and anorexia for 1 month was found to have multifocal lesions on radiological imaging.

DIAGNOSIS

HEH was diagnosed by needle biopsy. It can be seen from imaging that this case is a multifocal form. The largest lesion increased from 3 to 3.3 cm within 2 months, with an increase of 9.45%; no other relevant literatures have been reported.

INTERVENTIONS

The possibility of liver transplantation was suggested to the patient. However, the patient refused transplantation and was successfully treated by radical right hepatectomy and resection of the left lobe lesion.

OUTCOMES

She remained disease-free throughout a year follow-up period.

CONCLUSION

HEH is a rare disease with characteristic radiological and pathological features. Although liver transplantation is the preferred treatment for multifocal HEH, surgical excision represents one alternative when the lesions can be guaranteed to be completely excised.

Primary hepatic malignant vascular tumors: a follow-up study of imaging characteristics and clinicopathological features

Background

Owing to its low incidence, there is insufficient clinical awareness and diagnostic experience with primary hepatic malignant vascular tumors (PHMVTs). The aim of our study was to investigate the imaging and clinicopathological features of patients with PHMVTs and analyze the clinicopathological correlations.

Methods

We retrospectively analyzed 42 patients who had pathologically confirmed PHMVT during the period from June 2012 to December 2019 and enrolled them in our study. The computed tomography (CT) and magnetic resonance (MR) images and pathological findings of each patient were recorded.

Results

There were more female (29/42) than male patients. The imaging features of primary hepatic angiosarcoma (PHA) (n = 11) included ill-defined margins (11/11, 100%), necrosis (5/11, 45%), calcification (3/11, 27%) and “slow in-slow out” centripetal enhancement (7/11, 64%). Patients with epithelioid hemangioendothelioma (EHE) (n = 15) presented with ill-defined margins (15/15, 100%), necrosis (6/15, 40%), calcification (2/15, 13%), “fast in-slow out” centripetal enhancement (10/15, 67%), halo sign (15/15, 100%), pseudocapsule sign (4/15, 27%), lollipop sign (2/15, 13%) and capsule retraction sign (2/15, 13%). Patients with malignant hemangiopericytoma (MHP) (n = 3) showed ill-defined margins (3/3, 100%), necrosis (3/3, 100%) and “fast in-slow out” progressive enhancement (3/3, 100%). Infantile hemangioendotheliomas (IHEs) (n = 13) were defined by ill-defined margins (7/13, 54%), necrosis (8/13, 62%), calcification (5/13, 38%) and “fast in-slow out” centripetal enhancement (13/13, 100%). Immunohistochemistry showed strong positive expression of CD31, CD34, ERG, FaVIII and FLI-1. Patients with IHE (96 months) and EHE (88 months) had the longest survival times, followed by those with MHP (23 months), while patients with PHA (15 months) had the shortest survival time.

Conclusion

On CT and MR images, most PHMVTs were ill-defined, heterogeneous, hypervascular masses with centripetal progressive enhancement and possibly calcification, especially in female patients. The prognosis of patients with PHMVT was associated with the pathological type of the tumor.

Hepatic hemangioendothelioma: CT, MR, and FDG-PET-CT in 67 patients-a bi-institutional comprehensive cancer center review

OBJECTIVE

To evaluate the imaging features of hepatic epithelioid hemangioendothelioma (HEH) on multiphasic CT, MR, and FDG-PET-CT.

METHODS

Bi-institutional review identified 67 adults (mean age, 47 years; 23 M/44 F) with pathologically proven HEH and pretreatment multiphasic CT (n = 67) and/or MR (n = 30) and/or FDG-PET-CT (n = 13).

RESULTS

HEHs were multifocal in 88% (59/67). Mean size of the dominant mass was 4.1 cm (range, 1.4-19 cm). The tumors were located in the peripheral, subcapsular regions of the liver in 96% (64/67). Capsular retraction was present in 81% (54/67 cases) and tumors were coalescent in 61% (41/67). HEH demonstrated peripheral ring enhancement on arterial phase imaging in 33% (21/64) and target appearance on the portal venous phase in 69% (46/67). Persistent peripheral enhancement on the delayed phase was seen in 49% (31/63). On MR, multilayered target appearance was seen on the T2-weighted sequences in 67% (20/30) and on the diffusion-weighted sequences in 61% (11/18). Target appearance on hepatobiliary phase of MRI was seen in 57% (4/7). On pre-therapy FDG-PET-CT, increased FDG uptake above the background liver parenchyma was seen in 62% (8/13).

CONCLUSION

HEHs typically manifest as multifocal, coalescent hepatic nodules in peripheral subcapsular location, with associated capsular retraction. Peripheral arterial ring enhancement and target appearance on portal venous phase are commonly seen on CT. Similarly, multilayered target appearance correlating with its histopathological composition is typically seen on multiple sequences of MR including T2-weighted, diffusion-weighted, and dynamic contrast-enhanced multiphasic MR.

KEY POINTS

• Hepatic epithelioid hemangioendotheliomas manifest on CT and MR as multifocal, coalescent hepatic nodules in peripheral subcapsular location, with associated capsular retraction. • Enhancement pattern on contrast-enhanced CT and MR can vary but peripheral ring enhancement on arterial phase and target appearance on portal venous phase are commonly seen. • Retrospective two-center study showed that cross-sectional imaging may help in the diagnosis.

Hepatic Hemangioendothelioma: An update

Primary epithelioid hemangioendotheliomas of the liver (EHL) are rare tumors with a low incidence. The molecular background of EHL is still under investigation, with WWTR1-CAMPTA1 mutation may function as a tumor marker. Commonly, this tumor is misdiagnosed with angiosarcoma, cholangiocarcinomas, metastatic carcinoma, and hepatocellular carcinoma (sclerosing variant). Characteristic features on imaging modalities such as ultrasound, computed tomography, magnetic resonance imaging and positron emission tomography/computed tomography guide in diagnosis and staging. The "halo sign" and the "lollipop sign" on computed tomography and magnetic resonance imaging are described in the literature. Currently, there are no standardized guidelines for treating EHL with treatment options are broad including: chemotherapy, ablation, surgery and liver transplantation with inconsistent results.

Hepatic Epithelioid Hemangioendothelioma

Epithelioid hemangioendothelioma is a rare vascular tumor, composed of epithelioid and histiocytoid vascular endothelial cells in myxoid or fibrotic stroma, which can arise in multiple locations throughout the body. In the liver, this neoplasm usually presents on imaging as an incidental finding of multifocal, heterogeneously enhancing nodules in both lobes or presents clinically with nonspecific abdominal symptoms. Histologically, the tumor has been mistaken for metastatic carcinoma, angiosarcoma, hepatocellular carcinoma, and cholangiocarcinoma. The neoplasm usually stains positive for vascular markers, such as factor VIII-related antigen, CD31, and CD34, and negative for cytokeratins. The translocation t(1;3)(p36.3;q25), resulting in the CAMTA1- WWTR1 fusion product, is the most commonly identified genetic abnormality with this tumor. Although hepatic epithelioid hemangioendothelioma can have a varied clinical course, it is generally considered less aggressive than angiosarcoma. There is no consensus treatment protocol and techniques including liver transplantation, liver resection, chemotherapy and/or radiation therapy, and surveillance have all been used with varying outcomes.

The Feature of Solitary Small Nodular Type of Hepatic Epithelioid Hemangioendothelioma

Hepatic epithelioid hemangioendothelioma (HEHE) is a rare tumor. Preoperative diagnosis of HEHE is difficult because it does not manifest specific symptoms or tumor markers. We report a resected case of small and solitary HEHE. The patient, a 74-year-old man, had undergone surgical resection for left renal cell carcinoma 20 years ago. During follow-up, a tumor approximately 1.3 cm in diameter was detected by computed tomography (CT) at liver segment VIII. It showed isodensity in the arterial phase, low density in the portal venous phase, and homogeneous enhancement in the late phase on CT and magnetic resonance imaging (MRI). We performed hepatic resection of the right hepatic vein drainage area. A pathological diagnosis of HEHE was made. Although small and solitary HEHE is rare, an enhancement pattern in each phase on CT and MRI, using contrast media, can yield clues for the diagnosis of HEHE.

Hepatic epithelioid haemangioendothelioma (HEHE): a diagnostic dilemma between haemangioma and angiosarcoma

We present a case of a 77-year-old male patient with a liver tumour diagnosed as hepatic epithelioid haemangioendothelioma (HEHE), a potentially malignant tumour treated with liver resection. The patient is disease-free 3 years after resection. Imaging features using fludeoxyglucose F 18 positron emission tomography CT and MRI with gadoxic acid as well as histopathological findings are discussed.

Primary hepatic hemangioendothelioma in a patient with Budd-Chiari syndrome

A 36-year-old woman was diagnosed with compensated cirrhosis of liver secondary to Budd-Chiari syndrome (BCS) and had undergone stenting of a thrombosed left hepatic vein. Eight months later, she presented with jaundice and right upper quadrant pain. CT revealed multiple focal lesions in the liver, which on biopsy proved to be hepatic hemangioendothelioma (HHE). Her liver disease and ascites progressively increased. Four months later, magnetic resonance cholangiopancreatography showed an advanced stage of HHE with infiltration of the common bile duct and vascular invasion with a blocked stent, with metastasis to the spleen and dorsolumbar vertebrae. We believe this is the first reported case of an HHE developing in the background of BCS.

Hepatic Epithelioid Hemangioendothelioma and Adult Liver Transplantation: Proposal for a Prognostic Score Based on the Analysis of the ELTR-ELITA Registry

BACKGROUND

Hepatic epithelioid hemangioendothelioma (HEHE) is a rare vascular tumor which has an intermediate aggressive behavior. Although the value of liver transplantation (LT) is well established, its place in the management of HEHE is still unclear. The aim of this study is to confirm, based on a very large patient cohort, the value of LT in the management of HEHE and to identify risk factors for post-LT recurrence.

METHODS

The outcome of 149 transplant recipients with HEHE recorded in the European Liver Transplant Registry during the period November 1984 to May 2014 was analyzed. Median post-LT follow-up was 7.6 years (interquartile range, 2.8-14.4).

RESULTS

Cox regression analysis showed that macrovascular invasion (hazard ratio [HR], 4.8; P < 0.001), pre-LT waiting time of 120 days or less (HR, 2.6; P = 0.01) and hilar lymph node invasion (HR = 2.2; P = 0.03), but not pre-LT extrahepatic disease, were significant risk factors for recurrence. These findings, which were also confirmed in a propensity score analysis, allowed the development of a HEHE-LT score enabling stratification of patients in relation to their risk of tumor recurrence. Patients with a score of 2 or less had a much better 5-year disease-free survival compared to those having a score of 6 or higher (93.9% vs 38.5%; P < 0.001).

CONCLUSIONS

The analysis of this (largest in the world) HEHE adult liver recipient cohort clearly confirms the value of LT in the treatment of this rare disorder and also permits identification of patients at risk of posttransplant recurrence. Posttransplant follow-up should take the HEHE-LT score into account. Extrahepatic disease localization is reconfirmed not to be a contraindication for LT.

Spontaneous rupture of hepatic epithelioid hemangioendothelioma: A case report

Hepatic epithelioid hemangioendothelioma (HEH) is a rare tumor of vascular endothelial origin. Spontaneous rupture of HEH is a life-threatening complication and is extremely rare. HEH has variable malignant potential, and the clinical diagnosis remains challenging. Here we report a case of HEH with spontaneous rupture. A 44-year-old man presented with constant cutting pains over the right upper abdomen after eating. He had hemoptysis 11 d previously. Diagnostic abdominal puncture demonstrated active bleeding. Chest and abdominal computer tomography scan showed multiple ground-glass nodules over the lungs, multiple low-density intrahepatic nodules and massive hemorrhage. Transcatheter arterial embolization and exploratory laparotomy were performed and subsequent immunohistochemical examination confirmed a diagnosis of HEH.

Uncommon liver tumors: Case report and literature review

BACKGROUND

Beside hepatocellular carcinoma, metastasis, and cholangiocarcinoma, the imaging findings of other relatively uncommon hepatic lesions are less discussed in the literature. Imaging diagnosis of these lesions is a daily challenge. In this article, we review the imaging characteristics of these neoplasms.

METHODS

From January 2003 to December 2014, 4746 patients underwent liver biopsy or hepatic surgical resection in our hospital. We reviewed the pathological database retrospectively. Imaging of these lesions was reviewed.

RESULTS

Imaging findings of uncommon hepatic lesions vary. We discuss the typical imaging characteristics with literature review. Clinical and pathological correlations are also described. Primary hepatic lymphoma consists only of 1% of the extranodal non-Hodgkin lymphoma, and is defined as the one involving only the liver and perihepatic lymph nodes within 6 months after diagnosis. Combined hepatocellular and cholangiocarcinoma (cHCC-CC) shares some overlapping imaging characteristics with both HCC and cholangiocarcinoma because of being an admixture of them. Angiosarcoma is the most common hepatic mesenchymal tumor and is hypervascular in nature. Inflammatory pseudotumor is often heterogeneous on ultrasonography and with enhanced septations and rims in the portovenous phase after contrast medium. Angiomyolipoma (AML) typically presents with macroscopic fat components with low signal on fat-saturated magnetic resonance imaging (MRI) and presence of drainage vessels. Intraductal papillary neoplasm of the bile duct (IPNB) is thought of as a counterpart to the pancreatic intraductal papillary mucinous neoplasm. Most of the IPNBs secrete mucin and cause disproportional dilatation of the bile ducts. Mucinous cystic neoplasm (MCN) contains proteinaceous and colloidal components without ductal communication and characterizes with hyperintensity on T1-weighted imaging. Other extremely rare lesions, including epithelioid hemangioendothelioma and inflammatory pseudotumor-like follicular dendritic cell sarcoma, are also discussed. Hepatoblastoma and mesenchymal hamartoma, mostly in children, are also briefly reviewed as well.

CONCLUSION

It is important for radiologists to be familiar with the typical imaging features of the uncommon hepatic neoplasms. If imaging findings are not typical or diagnostic, further biopsy is required.